During the post-manufacture of semiconductor devices and printed circuit boards, the components (whether they be individual intergrated circuit devices or circuit boards containing integrated circuit devices) are subjected to a reliability test called "burn-in" prior to their shipment. The burn-in test is a functional test subjecting all the components mounted on a circuit board to a temperature and voltage condition for the purpose of separating the good product from the bad. In addition, IC chips and circuit boards often undergo functionality, performance, and/or failure analysis testing during the manufacturing or post manufacturing of such devices.
Electrical connectors for interconnecting circuit boards to testers and drivers are known in the art. Typically, such connectors possess contacting elements that extend from the connector to effect contact with respective contact pads (e.g., flat copper pads) located on an external surface of the printed circuit board. Contact is usually achieved through the use of some compression or clamping means that engages the contact elements with their respective contact pads. Zero insertion force (ZIF) card edge connectors are also known in the art and are used to overcome those problems associated with high insertion forces. One type of zero insertion force connector utilizes fluid pressure to actuate an expandable bladder located within a housing of the connector to exert a force against a flexible circuit. Electrical connection between the connector and circuit board is achieved by expanding the bladder to forcibly engage contact elements/pads on the surface of the flexible circuit with corresponding pads on the edge of the printed circuit board.
Although the use of pressure actuated zero insertion force connectors are known in the art, there are several problems that have yet to be overcome by current zero insertion force connector designs. Notably, during the manufacturing process debris and other contaminates accumulate and adhere to the external printed circuit board contact pads. Current pressure actuated zero insertion force sockets fail to account for the removal of debris, contaminates or other non-conductive layers that tend to form on the surface of external printed circuit board contacts.
As described above, fluid pressure actuated zero insertion force connectors typically use an expandable bladder to exert a force against a flexible circuit to thereby engage the contact pads of the flexible circuit with corresponding contact pads located on the printed circuit board. Although prior art fluid pressure actuators adequately address those problems associated with excessive insertion force, they do not adequately assure the complete disengagement of the connector contact elements from the printed circuit board contact pads prior to the removal of the circuit board from the connector. As a result, the life of the connector contact elements are effectively reduced as they drag or scrape against the circuit board contact pads during the removal of the circuit board from the connector. Moreover, the dragging or scraping of the connector contact elements tend to cause excessive wear or damage to the printed circuit boards contact pads.
Thus, what is needed is a method and apparatus for electrically coupling a printed circuit board to another electrical device, such as a tester, that solves the problems associated with current fluid pressure zero insertion force connectors.